The invention relates to a method of providing traffic condition data, to a system for transmitting traffic condition data, to a device in a motor vehicle for generating and emitting traffic condition data and to a computer program product for use in a motor vehicle and for generating and emitting traffic condition data according to the preamble of the concerned independent claim.
Known vehicles send so-called floating car data (FCD). The system used for this purpose consists of a GPS receiver and a GSM module. Both modules already exist in many vehicles even without FCD functionality. The GPS receiver measures the position, and the FCD processes determine travel times of the vehicle from many of these position data. By means of the GSM network, these travel times are transmitted as bead chains (individual points of the driving route provided with space coordinates and time stamps) to the traffic data control center. The latter can draw conclusions on the traffic situation from these travel times. In this manner, a data inquiry takes place with respect to vehicle condition data for traffic information services.
The data transmission by way of the GSM network is connected with considerable costs.
In order to, in the future, determine the traffic situation more precisely and, in addition, by means of information concerning weather, road conditions and local dangers, FCD is further developed to XFCD (Extended Floating Car Data). XFCD utilizes the diverse sensors and subsystems present in the vehicle, which even now make their data available on central data buses in the vehicle. The analysis of the diverse data during the drive can provide information on traffic conditions, visual impairments, road conditions (road surface), conditions of infrastructure (winding roads), local dangers, precipitation, slickness and dangers connected with slippery road conditions.
An object of the invention particularly is a method of providing high-quality traffic condition data at acceptable cost.
An aspect of the method according to the invention for providing traffic condition data within the scope of a traffic condition recognition by a motor vehicle, particularly traffic condition data for detecting the traffic situation, preferably traffic condition data for detecting traffic jams, consists of the fact that, in a first step, the type of road on which the vehicle is traveling is determined by using the position recognition device and the digital road map; in a second step, the category of the road on which the vehicle is traveling is determined by using the position recognition device and the digital road map; in a third step, an assignment, particularly a table, is used which assigns at least one lower speed threshold and one upper speed threshold to the corresponding road type as well as to the corresponding category of the road on which the vehicle is traveling; and, in a fourth step, at least the lower speed threshold and the upper speed threshold, if required, in a modified form, are used for determining the traffic condition.
As a result of these measures, a better estimation of the situation is permitted through different speed categories. Thus, the falling of the speed below the lower speed threshold is an indication that the vehicle is moving in a traffic jam or is standing still. A speed of the vehicle which is in the range between the lower and the upper speed threshold is an indication that the vehicle is moving in a more undefined condition between a traffic jam and unimpeded travel. A speed of the vehicle which is higher than the upper speed threshold finally is an indication that the corresponding vehicle is traveling in an unimpeded fashion. By means of this classification, it becomes possible to differently weight the above-mentioned conditions and therefore permit a largely reliable detection of a jam also under several conditions which occur during the observation time for deciding whether or not a traffic jam is present.
This increases the acceptance with respect to using the method according to the invention as a result of the rising reliability and saves costs for transmitting false traffic jam reports from the vehicle to an institution, particularly a traffic data center, which reconstructs and displays the traffic situation. In particular, these consist of costs for corresponding SMS (short message service) messages or costs for other types of transmissions.
It is understood that the movement or the speed of the vehicle can also be divided into more than three speed categories or speed ranges. This may be meaningful particularly when a differentiation is to be made not only as to whether or not a vehicle is in a traffic jam but also at which points of the traffic jam which average speeds should be driven.
By this method, particularly for providing traffic condition data for detecting the traffic situation in the entire road system, preferably for detecting traffic jams, it becomes possible to largely reliably recognize a traffic condition and to transmit the traffic condition as an existing traffic situation only when it is currently occurring; that is, the method according to the invention makes it possible to generate traffic condition data in an event-oriented and condition-oriented fashion. Traffic condition data are transmitted only when this transmission is caused by the recognized traffic condition, for example, by a traffic jam.
As a result, the data traffic to an institution reconstructing and displaying the traffic situation, particularly a traffic data center, preferably by SMS, and the costs of the data transmission are limited to the minimum required for representing the traffic situation, without impairing the quality of the traffic situation detection.
In view of the above, it is only the method according to the invention which permits a cost-effective and even still contemporary data extraction by the vehicle for the entire road system, particularly on highways, country roads and on streets in city traffic.
As an alternative or in addition, it is provided in an embodiment of the invention that the road type and the category of the road on which the vehicle is traveling are provided by the known standard sensor interface, abbreviated “SSI”, by using the local position of the vehicle provided in the vehicle and a road type assigned to the local position and a road category assigned to the local position.
As a result, no additional hardware or software is required for providing these data, which promotes a cost-effective implementation of the invention.
As an alternative or in addition, it is provided in an embodiment of the invention that the road types “highway”, “fast road”, “regional road”, “main road”, “local road”, “connecting road”, “slow road”, “minor road”, and “service road” are taken into account during the implementation of the method according to the invention.
As an alternative or in addition, it is provided in another embodiment of the invention that the road/street categories “in-town” “out-of-town” are taken into account during the implementation of the method according to the invention.
The consideration according to the invention of the above-mentioned road types and of the road category assigned to each of the road types permits a very precise classification of the expected speed level or of the lower and upper speed thresholds. This finally permits a largely reliable and nevertheless surface-covering detection of traffic jams on highways, country roads, city streets, etc.
As an alternative or in addition, it is provided in another embodiment of the invention that a normal speed is assigned to the determined road type as a function of the determined road category, and a lower speed threshold of approximately 35% of the normal speed and an upper speed threshold of approximately 45% of the normal speed are defined.
As an alternative or in addition, it is provided in another embodiment of the invention that speed values for a lower and an upper speed threshold defined as a function of the determined road category from a table of empirical values filed in the vehicle are assigned to the determined road type.
As an alternative or in addition, it is provided in another embodiment of the invention that current values for the lower and upper speed threshold, particularly as a function of the current vehicle position and of the time of day, are fed into the vehicle from outside the vehicle, particularly from a traffic data control center, and the current values are temporarily used instead of the original values.
The transmission of the current values for the lower and upper speed threshold for a route section which is currently being traveled or will soon be traveled preferably takes place into the vehicle by way of SMS, TMC, DAB or the like. The original data may be taken from a storage device in the vehicle (FIG. 6, 640), particularly a DVD, and only the currently deviating values are transmitted into the vehicle.
Vehicle-generated data are provided preferably every second to a computation algorithm by the vehicle data buses by means of a known standard sensor interface (FIG. 2, 201; FIG. 6, 630).
Furthermore, the method of obtaining data according to the invention permits the use of an advantageous system for the transmission of traffic condition data from a first vehicle to a second vehicle, particularly by way of an ad hoc network, or from a traffic data control center to one or more motor vehicles, if required, in a modified form, particularly by way of broadcasting. Likewise, it allows the use of an advantageous device and a computer program product in a motor vehicle for generating and emitting traffic condition data.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.